I gave OS3 a shot when it first came out maybe version 1.03 and really hated the record and trim mode screens in OS3, to me it was just awkward and felt backwards compared the to OS2XL record and trim mode screens. So I pretty much switched back immediately to OS2XL and really haven't been paying attention to what JJ has been doing in OS3 since then but I might reinstall OS3 at some point this year and see what improvements have been made to it.
MPC 1000|128MB Ram, 100GB HDD, JJOS 2XL
MPC 2500|128MB Ram, 40GB HDD, CD Drive, JJOS-XL
MPC 2000| 32MB Ram, Version 2 LCD, 8-outputs & EB16 FX Expansion